Determination of Ferulic andp-Coumaric Acids in Wheat Straw and the Amounts Released by Mild Acid and Alkaline Peroxide Treatment

1998 ◽  
Vol 46 (12) ◽  
pp. 5283-5288 ◽  
Author(s):  
George X. Pan ◽  
Jennifer L. Bolton ◽  
Gordon J. Leary
Keyword(s):  
Wheat Straw ◽  
Alkaline Peroxide ◽  
Mild Acid

scholarly journals Role of laccase as an enzymatic pretreatment method to improve lignocellulosic saccharification

2014 ◽  
Vol 4 (8) ◽  
pp. 2251-2259 ◽  
Author(s):  
Lucy Heap ◽  
Anthony Green ◽  
David Brown ◽  
Bart van Dongen ◽  
Nicholas Turner
Keyword(s):  
Wheat Straw ◽  
Trametes Versicolor ◽  
Enzymatic Pretreatment ◽  
Pretreatment Method ◽  
Alkaline Peroxide

The saccharification of wheat straw was improved when an incubation step was performed withTrametes versicolorlaccase (TvL) and the mediator 1-hydroxybenzotriazole (1-HBT) prior to an alkaline peroxide extraction (APE).

The synthesis of a carbohydrate-like dihydrooxazine and tetrahydrooxazine as putative inhibitors of glycoside hydrolases: A direct synthesis of isofagomine

2002 ◽  
Vol 80 (8) ◽  
pp. 857-865 ◽  
Author(s):  
Wayne M Best ◽  
James M Macdonald ◽  
Brian W Skelton ◽  
Robert V Stick ◽  
D Matthew G Tilbrook ◽  
...  
Keyword(s):  
Direct Synthesis ◽  
Glycoside Hydrolases ◽  
Crystalline Solid ◽  
Glycosidase Inhibitors ◽  
Protecting Group ◽  
Mild Acid Hydrolysis ◽  
Catalytic Hydrogenolysis ◽  
Palladium On Carbon ◽  
Mild Acid

The treatment of benzyl 2,3-O-isopropylidene-β-L-xylopyranoside with N-hydroxyphthalimide under Mitsunobu conditions, followed by protecting-group interchange, gave benzyl 4-O-[(tert-butoxycarbonyl)amino]-2,3- O-isopropylidene-α-D-arabinoside. Mild acid hydrolysis and catalytic hydrogenolysis afforded 4-O-[(tert-butoxycarbonyl)amino]-D-arabinose that, upon heating in water, gave the dihydrooxazine [(4R,5S,6R)-5,6-dihydro-4,5-dihydroxy-6-hydroxymethyl-4H-1,2-oxazine] as a crystalline solid. A single-crystal structure determination of this solid showed it to exist in the 5H6 conformation. Reduction of the dihydrooxazine gave the tetrahydrooxazine [(4R,5S,6R)-4,5-dihydroxy-6-hydroxymethyl-3,4,5,6-tetrahydro-2H-1,2-oxazine]. The dihydrooxazine was an effective inhibitor of two β-glucosidases (Ki = 27 and 35 µM). Benzyl 2,3-O-isopropylidene-β-L-xylopyranoside, via the derived imidazylate, was converted into a nitrile that, upon reduction and protecting-group manipulations, gave benzyl 4-C-aminomethyl-4-deoxy-α-D-arabinoside. Treatment of this amine with hydrogen and palladium-on-carbon gave isofagomine.Key words: dihydrooxazine, tetrahydrooxazine, isofagomine, iminosugars, glycosidase inhibitors.

INVESTIGATIONS ON RUBBER-BEARING PLANTS: II. CARBOHYDRATES IN THE ROOTS OF TARAXACUM KOK-SAGHYZ ROD.

1946 ◽  
Vol 24c (2) ◽  
pp. 47-53 ◽  
Author(s):  
Paul R. Gorham
Keyword(s):  
Reducing Sugars ◽  
Analytical Data ◽  
Dry Weight ◽  
Hot Water ◽  
Soluble Carbohydrates ◽  
Mild Acid Hydrolysis ◽  
Rubber Bearing ◽  
One Year ◽  
Mild Acid

The soluble carbohydrates were extracted, by means of hot water, from dried ground roots of Taraxacum kok-saghyz Rod. that had been extracted previously with acetone and benzene. A cleared portion of the extract served for the determination of hexose and, after invertase hydrolysis, sucrose. Another portion was subjected to mild acid hydrolysis before clearing, and served for the determination of total reducing value, whence fructosans, as inulin, were calculated. Separation of the free reducing sugars and sucrose from the fructosans by ethanol extraction proved unsatisfactory. Analyses of 171 one-year old roots from six crosses gave the following average values expressed as per cent dry weight: hexose 1.6, sucrose 4.7, and inulin 41. The analytical data suggest the possibility of selecting and breeding for strains of kok-saghyz capable of high carbohydrate production.

Synthesis of 2', 6'-Dihydroxychalcones by Using Tetrahydropyran-2-yl and Trialkylsilyl Protective Groups; the Crystal Structure Determination of 2',6'-Dihydroxy-2,4,6-trimethoxychalcone

1989 ◽  
Vol 42 (7) ◽  
pp. 1103 ◽  
Author(s):  
CO Miles ◽  
L Main ◽  
BK Nicholson
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bonding ◽  
Silyl Ether ◽  
X Ray ◽  
Protective Groups ◽  
Intramolecular Hydrogen ◽  
First Time ◽  
Mild Acid

Two improved general routes to 2′,6′-dihydroxychalcones are described in which the final step is protective-group removal from O 2′ under mild acid conditions. The first involves base-catalysed condensation of benzaldehydes with 2′-hydroxy-6′-tetrahydropyran-2-yloxyacetophenone, the second ring-opening of 5-hydroxyflavanones with 1,8-diazabicyclo[5.4.0]undec-7-ene in the presence of a trialkylchlorosilane to trap out the chalcone as a bis silyl ether. Chalcones prepared by the first route are 2',6'-dihydroxychalcone (1), and its 4-methoxy (2), 3,4-dimethoxy (3), 3,4,5-trimethoxy (4), and 2,4,6-trimethoxy (5) derivatives. The 4-chloro derivative (6) and the chalcone from hesperetin are prepared by the second method. .The X-ray crystal structure of 2',6'-dihydroxy-2,4,6-trimethoxychalcone (5), the first for a 2',6′-dihydroxychalcone, is reported, the hydrogen involved in intramolecular hydrogen-bonding between the carbonyl and phenolic oxygens being located for the first time for any 2'-hydroxychalcone derivative. The O 6' involved in the intramolecular hydrogen-bonding is also hydrogen-bonded intermolecularly to the hydrogen of the other (2'-)hydroxy group of a neighbouring molecule in the lattice. 13C n.m.r. data are the first reported for a series of 2',6'-dihydroxychalcones.

Collaborative Study of Acid-Detergent Fiber and Lignin

1973 ◽  
Vol 56 (4) ◽  
pp. 781-784 ◽  
Author(s):  
Peter J Van Soest
Keyword(s):  
Wheat Straw ◽  
Soybean Meal ◽  
Standard Error ◽  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Barley Straw ◽  
Acid Detergent Fiber ◽  
Collaborative Test ◽  
Definition Of

Abstract A second collaborative study on acid-detergent fiber and lignin has been completed involving 10 laboratories and 6 samples including timothy, alfalfa, soybean meal, barley straw, orchardgrass, and wheat straw. Results from 7 laboratories appeared normal according to the Youden collaborative test and yielded a mean duplicate error of 0.40±0.31, a standard error between laboratories of 0.40, and a coefficient of variation of 1.02%. The duplicate error for lignin was 0.23±0.31, the standard error between laboratories, 0.28, and the coefficient of variation, 4.26%. Results indicate problems with filtering, handling fritted glass crucibles in a uniform weighing procedure, and reliably preparing asbestos used in the preparation of lignin. Modifications of the previously published method include reduction of sample size to 1 g, elimination of the use of decalin, rigorous definition of filtration and weighing procedures, use of P2O5 or Mg(ClO4)2 as desiccant, and determination of a lignin blank. Problems in filtration can be overcome by not using more vacuum than is necessary, making all additions with vacuum off, and allowing 15–30 sec settling before applying suction. The modified acid-detergent fiber and lignin method has been adopted as official first action.

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